Changes

'''Sleep''' is a bodily state in which the body and mind rest. Almost all animals must sleep regularly to survive, but scientists are not sure why. However, sleep seems to play in important role in growth and memory processing, and sleep deprivation can lead to immune system deficiencies and a significant decrease in judgment and reaction time.

'''Sleep''' is a bodily state in which the body and mind rest. Almost all animals must sleep regularly to survive. However, sleep seems to play in important role in growth and memory processing, and sleep deprivation can lead to immune system deficiencies and a significant decrease in judgment and reaction time.

Sleep occurs in several phases, which vary in the type and intensity of the [[brain]] activity that occurs.

Sleep occurs in several phases, which vary in the type and intensity of the [[brain]] activity that occurs.